The specific idea we’ll focus on in this piece, is about the difference between “Massed Practice” and “Interleaved Practice” … One of these practices contributes to improved memory, long-term learning, and mastery of skills; while the other contributes to worse memory, faster forgetting, and zero mastery.

How to “make it stick” over the long run: Massed Practice vs Interleaved Practice.

“When the baseball players at Cal Poly practiced curveball after curveball over fifteen pitches, it became easier for them to remember the perceptions and responses they needed for that type of pitch: the look of the ball’s spin, how the ball changed direction, how fast its direction changed, and how long to wait for it to curve. Performance improved, but the growing ease of recalling those perceptions and responses led to little durable learning.

It is one skill to hit a curveball when you know a curveball will be thrown, it is a different skill to hit a curveball when you don’t know it’s coming.”

What the authors are explaining in the aforementioned quote is, that if the baseball players want to optimize their skills and become better athletes, they need to:

Spend LESS of their time practicing hitting curveballs when they KNOW they’re coming, and

Spend MOST of their time practicing hitting curveballs when they DON’T KNOW they’re coming

Unfortunately however, the players often do the reverse; spending countless back-to-back hours of hitting curveball after curveball with no surprises thrown into the mix to switch it up and keep them on their toes.

This way of practicing—of doing the same thing over and over again—is a form of massed practice, which builds performance gains on short-term memory.

Eventually, the authors split up the Cal Poly batters into two groups:

Group 1, the “massed practice“ group, hit curveball after curveball.

Group 2, the “interleaved practice” group, was thrown random pitches.

Which group do you think became better batters overall?

As you’ve probably already gathered at this point, the answer is Group 2—the one’s who started practicing with random pitches (aka: interleaved practice), which was more challenging + slowed their performance gains down significantly… But came along with the following upside: when they finally started building up their skills and got good enough to hit randomly pitched balls effectively—curveballs, straight throws, etc.—they retained these skills over the long-run; making them better batters as a result.

Even though Group 1, who hit curveball after curveball felt and looked like they were getting better, their gains didn’t last because they were only based on short-term memory.

Massed practice = faster forgetting (not good.)

“Practice that’s spaced out, interleaved with other learning, and varied produces better mastery, longer retention, and more versatility. But these benefits come at a price: when practice is spaced, interleaved, and varied, it requires more effort. You feel the increased effort, but not the benefits the effort produces. Learning feels slower from this kind of practice, and you don’t get the rapid improvements and affirmations you’re accustomed to seeing from massed practice.”

Massed practice—doing the same thing over and over again—feels good and leaves us with a perceived level of mastery (not good.)

A great example of interleaved practice might be randomly shuffling your flashcards every time you quiz yourself in preparation for an exam. Doing this, switches things up and prevents you from memorizing the order of the answers, since your brain won’t know which question/flashcard will pop up next.

Interleaving all the way: when learning for mastery—forget about massed practice.

Bottom line? When you’re learning something new, or trying to build up your skills at something—whether that something is sports-related, school-related, work-related, or anything else—be sure to make it a little bit more difficult than you’re used to, by simply switching things up/randomizing your practice, in order to get the best long-term learning results.

…In closing, when you discipline yourself to put forth the effort to engage in these types of learning practices, you’re going to benefit over the long-run.

So, unless you’re cramming for an exam on, I don’t know, the “history of drywall” or something, then it’s probably worth putting in the extra work to make sure what you’re learning about stays with you over the long-run.